Oil-well heater



Patented Aug. 22, 1922.

2 SHEETS-SHEET L H. PENNINGTON.

0H. WELL HEATER.

Avmcmuu mtu ocr. 29. |920.

HE PENNINGTON.

UIL WELL HEATER.

APFLIcAloN nuo ocr. 29. ls'zo'.

Patented Aug. 22, 1922'.

2 SHEETS-SINE' 2.

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wmaterial, athermostatarrangedin the wel .and .agrelayqin circuit with saidthermostut, ,20

. short circuitin .inclosed in a .Unirse STATES PATENT IOFFICE.

may rnNNnvG'roN, or

v'vv-icm'ra FALLS, "faxes,

OIL-WELL n nacrnn.

Specicatl'on of :Pfc: #known-'that Irllanzar Pmmmojron, ja citizen .o f' the United States A.residing-at Wichita Falls, in the .county of Wichita and .Statefof 1 eXas, -have ginvented certningnew and nsefullmprovemente in Oil-Well Heat ere, .af..nhj.hi-thf ,felleving -iS a .specicetion.l

. foil wellheajters, .and it comprises-a heater arranged in anJair tight-098mg .at thabotwmzofan onwel :Said

heater eultmunding the: wellftpbwnd eine separated. .there f;rom,by.a llayer .of heat'nsulating. material andlaA Llayer of air aniwa- .ter t1 hhmatenal,saidheatercornpris1ng Aa QQil ...0. ,reslstancepr Yheating?.wires.arranged nraboiy of cement of electrical refratnry nnd.- adeptedyswhenenergized '1e-.fopen a switch 4in .the maintcircult -and cut oli the of current .,to, the heatergaila. more o r. .asxhalt..;. The viscosity Aor' crude .oil is relative high and it does not flowzi-'eadilyv I t is-tliere ore impossible, underpresent methods, to obtain veryefficient-extrantions. A l l A The present invention relates to a method of., extracting oil from wells, wherein the oil is heatedto, reduce its viscosity-and lower the capillary attraction between the oil and AAsand' whereby the oil flows more readily and ma be removed from the pil sani. When t ew isheated, the paraffin orasphalt is li uefed,` .permitting the oil to flow .more free y through 'the pores of the sand.

a larger pencenta Several methods of removing oil from wells-whereinaheater is placed in the bottom ofthe well, have been proposed, but

suchmethods have not been wholly satisfactory. In some cases, hea-ting wires have been arranged in the well in an exposed position and water, especially -salt water, comingfin AContact with the ,wires .has caused and corrosion. To elimilatethe dilicu ty the heating wires have but no eicient mea-ns have been provided, for transmitting 65 the heaty outwardly to the oil sand. Air is .ofj transmitting or Lettera Patent.

-Appumioa med october 29,1920.' serlarno. 420.493.

ng poonlieat conductor and in such constructions, lt has generally been necessary.. to translmt the heat through air in the 4casing ofthe heater. 4

., In heaters for wells, it is also necessary to control l the heat to Prevent heating bevond a ,desired degree. I too muclrhent is furfnrshed,l the lllghter and more valuable con- .stltuents of t eoil are va orized and lost .and theface of the oil san becomes covered .with petroleurncolre, whichjs detrimental tp the further yrecovery ofoil.,

AIn the a. beutel.; .ranged .in

resent invention, .I have provided o r wherein the heater is arannir tight casingito remove `the gosslblllty .of short circuiting,land .an efcient Vconductor is provided for the purpose I radiating the heatl o o utnjardlgl to the oil lbearing sand. The inventlon rther comprises means for prevent- 0' radiation of heat inwardly-to the oil ubc, thereby preventing further heating of the oil after it has been extracted.

In.the present invention, I have also provided means `for controlling the temperature in the well to prevent'heatxng beyondn predetermined degree. .Said means comprises a .thermostat so arranged that it may be o erated without the necessity of additional cad wires running into the well and without the .necessity of grounding the main circuit which is of comparatively high volt ce.

In the accom anying drawinggnl have shown one embo iment of this invention. In this showing,

Figure 1 1s a partial sectional view of a well casing showing the well tube and heater in osition.

igure 2 is a vertical sectional vview through the lower end of the tube showing the heater in position.

Figure 3 is a horizontal sectional view on the line 3 3 0f Figure 2.

Fi ure 4 is a diagrammatic illustration of the e ectric circuits, and

Figure is u. detail perspective view showing one manner of winding the heating wires.

Refeirin to the drawings, the reference numeral 1 esignates a well casing having a well tube 2 arranged therein.- The well tube is of the usual sectional construction. A. portion of the derrick platform 3 arranged above the well in the usual manner is shown and the usual operating mechanism (not shown) is arranged adjacent the top of the welh "The heater lcomprises a casing 4 arranged around the lower section of the Well tube and providedjyith end closures vand 6 at the top and bottom, the vclosures being sealed or otherwise arranfred to prevent lentrance of air and Water. layer of heatinsulating .material if larranged Aaround the `v`vellt`ub`ef suitablehe'at insulating Inal terial may be employtlffnedfi'the forms of insulating material I find to be advan tag'eos 'isl ltllselguhr, :1" Kiels'elgul is 'mixed with waterto form enfrentan-d tfhen placed on the tube 'to the prpe'r 'thickre'ss'and dried. A thin ytube 8 of metal rtotherinonl`porous material is 'then'arangedover the layer of heat insulating jmate'r'ialaiid Sealed at the toplandbottom.; 'Thevv'i'res o'f "the electric-*heater 'areeiil'be'ddedi inL anelectrical refractoryfement 410,'iw'vlrichfis a "good concausin shrtfciriiiti ,"the airtn'ay be exhauste from thelannularv space between the tubeSandthe ras'inglsealed. "I have found, jhotever,` .that 'this method does not Vprovide la 'g'ood'onductro h'eat'lin thefele'ctrical refratory material, tantigitis advantageous to saturate'fthe'material 1(),i'n"which the heating wies`arefeinbedded,' 1vand its'pores with 'u' Apetroleum fractionhat` isE a goo'd conduc- 'tor 'of heatl" For this purpose. I preferably employ a transformer oil with a'high flash- !ing pointf' The thermostat "ll is arranged 'within the casing of the heater and comprises two rir- 'c'ular strips of lnetall and13 -`surrtnuiding; 'the well pipe 2`andsecu'red thereto atene end as at 14. The opposite ends thereofl are p'rdv'idedvith-a contact 15A adapted toengage the Contact 16 carried by vthe casing of theheater vand insulated l'th'erefrom'as at 1T. The circuits whereby current is 'conveyed to the heater and the heating coil short :fir- `cuited `when the thermostat closesthe con- Facts and 1.6, is diagramuiatically shown in'Figure of the drawings. The reterom-e numerals' employed in the otherhgures are Qmployed in'f`this figure to represent thc thermostat contacts and "the heating roll. As shown in this ligure, a pair 'of lead wires 1,8 and 19 is connected to the coil and extend to a source ofA current 20, which is "tio through vthe electrical 'refractory material `may be vaporized and lost.

usually arranged out of thef'well at-a convenient point. The thermostat is connected to one of the lead Wires. by Wire 21 having suitable resistance 22 arranged therein. The

f:contact 16 is connected to a ground by wire 23. A transformer coil 24 is connected to the two lead wires by wires 25 and 26,. and is adapted to energize a secondary coil 27. The coil f2? is connected to a relay 28 which is connected to a wire 29 leading to a ground. A switch 30 is arranged in themain lead Wire '19 and is :adapted to be opened when `the relay coil is energized by the closing of the contacts 15 and 16.

In Figure 5 of the drawings, there is shown one method fof arranging the Wind'- ings of the heater to a'voidinductance; In'- duclance caused by the windings aroundthe Well pipe Will lheat the 'Well pipewliich is disadvantageous.z When the wire is arranged vin double helir'with the wireso'fthe 4two hel'ixes parallel `to 'each other, inductance Will be reduc-ed' toa"mi"nim'um.` l i lV ith the well heater of the 'type shown, very efcient lr'e'sults can be obtained. "The heat generated 'isftransmitted outwardly which is a'g'o'o'd conductor of electricity,r and the outer-casing l4 to the'oil sand.' 'The casing being made air"tight 'dange'rof short circuitingdue to thel collection'ot`moisture contained vin'th'e air 1s obviated. As stated, in `some forms of the invention, T find it advantageous to' saturate the electrical 'refractory material 'withalpetroleum fractionjsu'ch as transformer oil for the purpose 'of-increasing the conductivitytliereof. When the oil has been :extractedfro'm the sand,-it is no longer desirable to 'further heatit. VIf the oil that has entered the Well 'pipe is further heated, 4there is a possibility that some ol the lighter and valuable fractions It is therefore highly important to prevent the transmission of heat inwardly to the well pip'ean'd this is accomplishedfin the 'present construe tion by means of the layer'of heat insulating material 7. Y j Y Y The thermostat is employed to prevent orereheating'ot the oil sand andthe for mation of petroleum coke. In operation, when the switch 30 is closed, the main circuit is completeand current is transmitted to the heater 9 through the main lead'wire's 18 und 19.4 lVhen the contacts l'and 16 of the thermostat are closed7 current passes through the coil 27,` the resistance Q2. the relay 2S to then'ires 29 and 23, leading to grounds; and `thus completing a circuit; The switch 3() is then opened and the main cirruit broken. The thermostat and relay 'are so arranged thatit'is only necessary Eto employ tnoV wirestrom the sourceof current to the thermostat and heater arranged :nl the bottom of the well, or a single vire where the circuit is grounded and the well pipe forms a part thereof. The provision of the transformer coils 24 and 27 lowers the voltage of the current passin through the grounds and removes the ob]ection of having a current of high voltage grounded.

A further advantage of the provision of a transformer to produce a current of 10W voltage passin throu h the thermostat is that the possi ilit o arcs caused by the making and brea ing of the contact by the thermostat is reduced to a minimum.

It is to be understood that while I have described the preferred embodiment of my invention, various chan es in the shape, size, and arrangement o? parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

l. In combination with the well pipe of an oil well, of an electric heater arranged adjacent the lower end thereof, said heater comprising a layer of heat insulatin material surrounding the well pipe, an alr and water tight casing surrounding said heat insulating material, a layer of electrical refractory material surrounding said casing, and electrical heating wires embedded therein.

2. In combination with a well pipe of an oil well, of a heater adapted to be arranged adjacent the lower end thereof, said heater comprising a layer of heat insulating material surrounding said tube, a layer of electrical refractory material surrounding said heat insulating material, heating wires embedded therein, and an outer air and Water tight casing surrounding said electrical refractory material.

3. In combination with a well pipe of an oil Well, of a heater for said well comprising an air and water tight casin arranged a jacent the bottom of said we 1 pipe, electric heating wires arranged therein, said heating wires being embedded in a layer of electrical refractory7 material saturated with a fluid of high dielectric strength, and a layer of heat insulating material disposed between said heating wire and said well pipe.

4. In combination with the well ipe of an oil well, of a heater for said wellpcomprising a casin arranged adjacent the bottom of said wel pipe, electrical heating means arranged therein, means for transmitting heat outwardly through said casing, means for preventing transmission of heat inwardly to said Well pipe, a thermostat arranged in said casing adapted to establish an auxiliary circuit when a predetermined temperature is reached, a relay arranged in said auxiliary circuit, and a switch in said main circuit adapted to be opened by said relay when the relay is energized.

5. In an electric heater for oil wells, s. casing arranged adjacent the bottom of the well, electrical heatin means arranged therein, a pair of electrlcal conductors connected to said heater and adapted to transmit current thereto, a thermostat arranged in said casing, said thermostat being connected to one of said conductors and to a ground, a relay coil arranged in circuit with said thermostat, and a switch arranged in the other conductor and adapted to be opened when said relay is energized.

6. In a heater for oil wells, the combination of heating means arranged adjacent the bottom of said well, a pair of conductors connected to said heater and to a source of current, a thermostat connected in parallel with one of said conductors and to ground, a transformer having one coil connected to each of said conductors, a relay coil connected to said transformer and to a ground to establish an auxiliary circuit when said thermostat is closed, and a switch arranged in one of said main conductors and adapted to be opened by said relay when the relay is energized.

In testimony whereof I affix my signature.

HARRY PENNINGTN. 

